SonicBlueSVT is correct. It is a pressurized hose off the power steering pump. The hose you modify is only to supply the p/s with the fluid.
I had it replaced under warranty the FIRST time it happened, but now they are refusing warranty claims. Apparently Ford has gotten a lot of calls from service centers regarding this exact problem. It's funny because the SVT has this hose break whether FI or NA, but now that more than one FI engine has come down with this problem they've red flagged it. The service manager told me today that when they called the SVT Tech Hotline about my having a 2nd broke p/s, they actually flat out asked my dealer if I had the JRSC before they even told them. They said they have some special part they can throw on that should take care of the problem -- out of warranty of course. Sounds like BS...but who knows.